(1) Field of the Invention
The invention relates to a sealing arrangement particularly applied to the scroll type compressor to adjustably avoid leakage in operation.
(2) Description of the Prior Art
In the art, while in cranking up a compressor, a rapid pressure boost is required to prevent the working fluid from possible stroking back. Also, the pressure shall be controlled in a reign so that the accumulated pressure won't be too high to damage the scrolls or the compression elements of the compressor, especially to those with a high compression ratio.
In U.S. Pat. No. 6,059,549, an improved high-low pressure chamber sealing arrangement for a volute compressor is disclosed, in which a single air chamber is formed by coupling a gliding block and scrolls. As the compressor is actuated, the gliding block can be pushed upwardly by the pressure variation in the air chamber and the spring force to support the partition block, such that the fluid in the high-pressure chamber can be inhibited to leak to the low-pressure chamber so as to quickly build up the pressure. However, a clear drawback of such an arrangement is that the force to lift the gliding block is close to zero at time of cranking up the compressor or at times when the compression ratio is too low. Under such situations, the gliding block is quite possible unable to overcome the friction and the weight itself to motion upwardly, and thus leakage or failure of building up the pressure may be expected. To resolve the foregoing problem, additional spring force is required to push the gliding block. On the other hand, when the compression ratio is too high, the resultant force from the gliding block and the spring element may make the gliding block unable to motion downwardly so as to relieve part of the load, and thus the reliability of the compressor is definitely degraded.
In US Pat. Pub. No. 2004/0126246, the difficulty in assembling the combination of the gliding block and the O ring into the receiving chamber makes impossible the mass production of the compressor. Also, in assembling the combination, the O ring is vulnerable to be cut by the chamber and thus may be damaged to induce further leakage which will definitely affect the service life and the reliability of the compressor.